archive mirror
 help / color / mirror / Atom feed
From: Daniel Jordan <>
To: Roman Gushchin <>
Cc:, Michal Hocko <>,
	Johannes Weiner <>,,,
	Vladimir Davydov <>,
	Shakeel Butt <>
Subject: Re: [PATCH] mm: slab: make page_cgroup_ino() to recognize non-compound slab pages properly
Date: Wed, 30 Oct 2019 17:03:14 -0400	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

Hi Roman,

On Fri, Oct 25, 2019 at 04:27:10PM -0700, Roman Gushchin wrote:
> page_cgroup_ino() doesn't return a valid memcg pointer for non-compund
> slab pages, because it depends on PgHead AND PgSlab flags to be set
> to determine the memory cgroup from the kmem_cache.
> It's correct for compound pages, but not for generic small pages. Those
> don't have PgHead set, so it ends up returning zero.
> Fix this by replacing the condition to PageSlab() && !PageTail().

You may also want to update the comment above memcg_from_slab_page():

 * So this function assumes that the page can pass PageHead() and PageSlab()
 * checks.

  parent reply	other threads:[~2019-10-30 21:04 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-25 23:27 [PATCH] mm: slab: make page_cgroup_ino() to recognize non-compound slab pages properly Roman Gushchin
2019-10-30 19:40 ` Roman Gushchin
2019-10-30 20:40 ` Shakeel Butt
2019-10-30 21:03 ` Daniel Jordan [this message]
2019-10-30 21:35   ` Roman Gushchin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).